A collection of letters from Chamberlain to John Nicholson of the War Department's Gettysburg National Park Commission are still held at Gettysburg National Park.
Along with the direct correspondence to Nicholson, copies of the correspondence between Chamberlain and William Oates were also sent to Nicholson.
Oates had hoped to place a monument to the 15th Alabama near the spot where he believed his brother and others had fallen. However after visiting the battlefield several times Oates admitted that
he was "confused in directions."1 He was not alone in his confusion as Chamberlain had declared in the dedication of the 20th Maine monument
that "I am certain that the position of this monument is quite to the left of center of our regimental line when the final charge was ordered."
After several attempts to address all three battlefield commissioners Oates wrote again, this time directly to Commissioner William M. Robbins, a one-time major in the 4th Alabama and the only Southerner of the three commissioners.
Surprisingly rather than approve Oates' request Robbins asked his other two commissioners for their support in turning Oates down, feeling that the commission "should not favor giving any single regiment on either side conspicuous notice."2
Robbins wrote back to Oates his denial of Oates' proposal citing a restriction established by the Gettysburg Battlefield Memorial Association in 1887,
"The monument must be on the line of battle held by the brigade."3
This restriction would place the monument along Confederate Avenue.
Refusing to accept this position, Oates wrote to Nicholson, the chairman of the battlefield commission, threatening to take his case to the Secretary of War via Congress.4
Meanwhile Commissioner Robbins, who himself had been part of the attack on Little Round Top, was growing suspicious of Oates' claims, and expressed his doubts of Oates' accuracy to Nicholson.5
Both commissioners decided to seek further evidence. While Robbins wrote to Evander Law their one time brigade commander, Nicholson wrote to Chamberlain including a copy of one of Oates' letters seen here.
While reassuring Chamberlain that the commissioners believed the monument, "should not be placed [away] from the Brigade but on the Confederate Avenue facing the Union positions.”
He asked Chamberlain's opinion on Oates' claims stating, “some of the statements are so much at variance with the records that we thought we would ask your opinion upon the subject.”
There is no evidence that Law responded, however Chamberlain did. (See documents on left)
While Chamberlain stated that he had no objection to a monument, he did balk at Oates' claim that Oates had turned his right flank and that Oates had engaged the 44th New York.
Receiving word of Chamberlain's objections and believing that the progress of the monument was being held up by Chamberlain, Oates wrote to him directly.
In his response Chamberlain assured both the Park Commission and Oates that he had no objection to the placement of the monument and believed that decision lay in the Park Commission's hands, he did
however reaffirm his earlier statements that disputed Oates' position for the monument.
Very few Confederate monuments were erected at Gettysburg, and by Nicholson's tone and the commissions repeated insistance in adhering to the battle line rule,
it seemed highly doubtful that a monument would have been erected even if Chamberlain had agreed with Oates on the details of the battle.
After receiving a copy of Chamberlain's last letter to Oates, Nicholson wrote Chamberlain, " I wish to congratulate you upon the dignified, manly, soldierly and gentlemanly way in which you have replied to him.
It is very clear that General Oates has not the slightest idea of admitting the views of any one in the controversy except himself." Nicholson went on to say that the commissioners would be leaving the final decision to the Secretary of War.6
Oates continued to fight the battle line regulation in Congress, however in 1910 Nicholson succeeded in getting the Secretary of War and the President to confirm the rule, thus ending once and for all the hope of an Alabama Monument on Little Round Top.7

(One letter from the previous conversation Chamberlain had with Oates that Chamberlain
mentions on page 9 can be seen at: learn.bowdoin.edu)

(The pencil marks on this copy that are darkening words were done by a modern day researcher. All other marks are original.)